Modoc sucker - U.S. Fish and Wildlife Service

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1930’s, without substantial assistance, and neither land nor water management in Modoc sucker streams is likely to change in the near future. Climate change is likely to make droughts worse and have other adverse effects on Modoc suckers, but current data are insufficient to identify the level of threat it poses. We are aware of no additional factors likely to threaten the Modoc sucker. III. RECOVERY CRITERIA Recovery Criteria from the 1984 Recovery (Action) Plan (USFWS 1984): Downlisting Criteria – “Consider reclassification to ‘threatened’ upon establishment of pure, safe populations (for 3 to 5 years) throughout Rush and Turner Creeks watersheds.” Delisting Criteria – “Consider delisting upon establishment of pure, safe populations (for 3 to 5 years) throughout Rush and Turner Creeks watersheds (downlisting criteria), and in two additional streams within historic range.” These downlisting and delisting criteria address the listing factors that are relevant to this species (Factors A, C, and E). Recovery tasks identified in the 1984 recovery action plan can be divided into 5 categories: 1) improve and secure habitat; 2) reduce threats from hybridization and perform genetic studies to assess degree of introgression; 3) expand range; 4) monitor populations; and 5) perform recovery-related administrative tasks. All recovery tasks from the signed 1984 recovery action plan and subsequent draft action plans are completed, ongoing, or have been deemed inappropriate, based on current information or policy (Reid 2008c). A summary of the recovery tasks and the status of the tasks is presented in Appendix A. IV. SYNTHESIS Most threats to the Modoc sucker that were considered in the 1985 listing rule (e.g., habitat modification, range reduction, and hybridization) have undergone substantial improvements or been ameliorated by new information and improved technology such that they no longer threaten the continued existence of the species. Habitat conditions on both public and private lands have shown substantial improvement, with continuing upward trends and a reasonable expectation that similar land management practices will continue. The distribution of known populations has remained stable or expanded slightly over the last 20 years, through a number of regional droughts. In addition, the range of the Modoc sucker has been expanded with the discovery of additional populations and documentation of genetic integrity in populations originally considered lost through hybridization. A greater understanding of the genetic relationships and natural gene flow between the Modoc and Sacramento sucker has reduced concerns over hybridization between the two naturally sympatric species. The principal remaining threat to the Modoc sucker is predation by non-native fishes, in particular brown trout in the Ash Creek sub-drainage and largemouth bass in the Turner subdrainage. While the Modoc sucker has survived for decades in the presence of non-native fish, if left unchecked introduced fish predators have the potential to threaten the Modoc sucker with 26
local extinction in at least one of three sub-drainages. Additional work is needed to understand the effects of non-native fish to the survivability of Modoc suckers and to develop a long-term management plan to address these effects. The best available information indicates the Modoc sucker is not in imminent danger of extinction because populations are more widespread than at the time of listing, most of the threats have either been eliminated or are no longer pertinent because of new information (e.g., range reduction and hybridization), or the threats are being addressed and conditions are improving (e.g., habitat modification and non-native fish predation). Therefore, we conclude that the Modoc sucker is no longer in danger of extinction and we recommend that the species be downlisted to threatened. In section VI below, we recommend actions that, if successfully implemented over the next 5 years, will further improve the conservation status of the species and provide additional information that would enable us to recommend delisting in our next 5year review. V. RESULTS Recommended Listing Action: _X__Downlist to Threatened ____ Uplist to Endangered ____ Delist (indicate reason for delisting according to 50 CFR 424.11): ____ Extinction ____ Recovery ____ Original data for classification in error ____ No Change New Recovery Priority Number and Brief Rationale: In the 2008 recovery data call we recommended that the priority number be increased from 8 to 14 because the species has a low degree of threat and a high potential for recovery). Listing and Reclassification Priority Number and Brief Rationale: Based on the Service’s Endangered and Threatened Species Listing and Recovery Priority Guidelines (48 FR 43098), a reclassification priority number of 4 is appropriate because the action would have a moderate management burden and would be an unpetitioned action. 27
Page 1 and 2: Modoc Sucker (Catostomus microps) 5
Page 3 and 4: the time of listing. In this review
Page 5 and 6: Information on the Species and its
Page 7 and 8: Figure 2. Map showing detailed dist
Page 9 and 10: introgressed character and full sym
Page 11 and 12: Willow (15), Ash (200), Dutch Flat
Page 13 and 14: Table 2. Comparison of available an
Page 15 and 16: Five-Factor Analysis The following
Page 17 and 18: suckers and were, therefore, exclud
Page 19 and 20: needed. However, current informatio
Page 21 and 22: with Modoc suckers contain no non-n
Page 23 and 24: streams typically associated with t
Page 25: There is no record of how frequentl
Page 29 and 30: VII. ACKNOWLEDGEMENTS The Service a
Page 31 and 32: ODFW [Oregon Department of Fish and
Page 33 and 34: USFWS [U.S. Fish and Wildlife Servi
Page 35 and 36: 1. Install and maintain fish barrie
Page 37: 4. Cooperate with private land owne

Modoc sucker - U.S. Fish and Wildlife Service

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